As is generally known in the art, use has been made of varying kinds of illumination lamps for lightening or illuminating objects at night or indoors. Such illumination lamps are supplied with electric energy from a power source and convert the electric energy to light energy, thereby producing a beam of light for illumination. Typical examples of the illumination lamps include a glow lamp and a fluorescent lamp.
Widely used in recent years is a Light Emitting Diode (LED) illumination lamp that has a benefit of providing illumination of different colors, although higher in price than the typical lamps referred to above. However, the LED illumination lamp poses a drawback in that it tends to be heated up and shows decreased efficiency when used for more than a predetermined time period. Use of the LED lamp for a prolonged period of time may result in excessive heat generation, thus shortening the life span of the lamp.
A number of solutions have been proposed to the problem of excessive heat generation and life span reduction, one example of which is disclosed in Korean Utility Model Registration No. 20-0336197.
A front lightening LED lamp taught in the '197 registration includes, as shown in FIGS. 1a and 1b, a heat radiation fin 1 having a cylindrical partition wall 1b integrally formed with a center part 1a, a cooling fan 2 received in the cylindrical partition wall 1b of the heat radiation fin 1 for forcibly circulating the air, a circuit board 3 for rectifying alternating current to direct current, a socket 5 attached to the end of the radiation fin 1 and electrically connected to a receptacle for a glow lamp, and a printed circuit board 4 having a plurality of LEDs 4a and mounted on the top of the center part 1a of the heat radiation fin
1. Each of the LEDs 4a is coated with a transparent cover 4b. Also provided is a transparent lens 6 that allows light to pass therethrough.
With the construction set forth above, the front lightening LED lamp of the '197 registration can exhibit increased illuminance with reduced energy consumption, provide proper intensity of illumination in compliance with the needs of a user by way of employing a structure that permits the user to directly affix LEDs to the front side of the lamp and thus confining the direction of light irradiation to a frontward direction, and attain cooling efficiency great enough to assure that the cooling fan can fully demonstrate its performance even when in continuous use, thereby extending the life span of the lamp.
The front lightening LED lamp of the '197 registration, however, poses a problem in that it is difficult to illuminate an object with decorative light of different colors because a transparent lens or cover allows the light emitted from LEDs to transmit therethrough without any color variation. Another drawback is that the external appearance of the lamp is marred by the LEDs remaining completely exposed to the outside through the lens. A further shortcoming resides in that the lamp is complicated in structure and costly to manufacture because a separate cooling fan has to be employed to forcibly dissipate the heat generated by the LEDs. Moreover, use of the cooling fan may lead to increased consumption of electric energy and generate additional heat by itself, thus adversely affecting the surrounding components inclusive of LEDs.
In addition to the disadvantages mentioned above, the front lightening LED lamp of the '197 registration has a further problem in that the connection or coupling between lamp components is too weak to provide an acceptable degree of hermetic seal, anti-vibration and waterproofing, which may result in reduced reliability and shortened life span of the lamp.